Looking for a RWD Chair with center foot plate in the US

[Burgerman]

had a FWD chair for a week and for the life of me I just could not get the hang of that thing.

Just felt weird and slightly out of control all the time. I don't really understand why.

Simple physics. The centre of gravity (C of mass really) was behind the centre of pressure. Thats an unstable situation that wants to spin the chair around and face the opposite way. And it would do so without some electronics to prevent this. To try and stop this they use an electronic gyro. Which is like adding a sticking plaster over a wound. It usually almost fixes the spin out problem by adding "turn power" to the motors to keep it straight. But has to take over control from the joysticks input YOU choose in order to do so. So at times its using all or most of the turning power available already with "opposite steer" to try and stop its ass end from flying out wide. So its leaving non for you to use to steer. You feel this as the chair not doing what you tell it. Such as when accelerating and turning. And yes it feels horrible. I have no idea how on earth people that claim its great can NOT FEEL this. To me its patently obvious and it stops me ever wanting one as a gift. You can try to disguise the issue but you cant actually beat the physics thats happening anyway.

Front drive / rear casters = unstable platform. So introduce a slight turn and it naturally wants to increase that and the more it does, then the more it tries to increase the turn. So it really "wants" to spin around. And it tries to do so. Gets worse exponentially as you go faster. Cannot ever be programmed PROPERLY.

Mid drive is neither stable or unstable, known as neutral. Some of these have gyros. But dont need them once programmed PROPERLY. They neither tighten up a turn nor straighten naturally. It wants to continue whatever turn rate you introduce forever with no further input.

Rear drive is a stable platform. If a slope, bump or turn is introduced by terrain, or by driver its natural tendency is to straighten up naturally by itself. Just like your car. It "wants" to go straight. So does so. A gyro is pointless unless you are driving with switch non proportional controls. It already naturally does what a gyro attemps to for front drive chairs.

***************

Or:

MID neutral equilibrium:
a state of equilibrium that is independent of a system’s displacements from its original position

REAR stable equilibrium:
a system, when displaced, experiences a net force or torque in a direction opposite to the direction of the displacement

FRONT unstable equilibrium:
a system, when displaced, experiences a net force or torque in the same direction as the displacement from equilibrium

[fishinjunky]

this is just a theory but one of the reasons sunrise doesnt offer the q500r and q700r may be because of insurance codes. Here in the U.S Medicare, Medicaid and most insurance companies will only cover group 3 coded chairs. If its a group 4 chair insurance most of the time wont cover it. When people get chairs here they have to go through a therapist or a A.T.P and they will only recommend chairs that are group 3 they wont even talk about group 4 chairs unless your over weight and need a group 4 HD chair. Most people here blindly go with what the therapists recommends. So they probably sell less of them here in the U.S. thats if they are group 4.

just a theory

[expresso]

its up to the manufactors to make a RWD chair that falls under a group 3 standard -

usually group 4 chairs are just speed - motor differences - not much more else like 646 vs 636 - same chair - dont know why they even made two different chairs - only difference was the motors

and the P220 and P222se - same thing - thats all history now - no longer on there website - - the 500H is the only chair there under RWD

and its not a real RWD -

there is no reason they can make a RWD to group 3 codes - also if you insist on a group 4 chair - better have a good reason to justify it over a group 3 chair - they need to make a medical letter to justify it - and if denied - you have to appeal and go to a fair hearing most likely

dosnt mean you wont get it - you can win and most do if you go the whole nine yards with it - but they will try not to do it the ATP and OT etc, they dont want to do the extra effort and then chances or loosing - wasting time etc, - but if you wanted it - you need to force them to do it put it in and let you fight it -

[Burgerman]

The reason appears simple. In the rest of the world users are floating about waving cash at powerchair sellers. If you want a q700, with all the good parts you wont get that from WCS/NHS. But I see lots around here. So £££ is king. Same in the rest of the EU and most of the world. So the manufacturer has to offer what the end user wants at a sensible price. Just as in a scooter, car, sofa, kitchen, and every other market. Want a new car? They fall over themselves to offer every possible customization, style, type and colour. Because thats capitalist free markets in action. All fighting for a sale, your money.

No rear drive options? You lose the sale to a company that does have one. Thats free market capitalist forces at work.

In the US theres no hoards of people running around making these choices based on wants, prices etc. So you basically do as you are told and get what they decide.

Everything else in america is free market capitalism. Except the non free over regulated medical care/insurance system. And thats your problem. Everything is made to fit in with the group 3/4 or whatever, and whatever sells the most model/spec. YOU dont decide. They dont care as YOU are not paying.

[expresso]

yes the insurance has a guide line to meet those specs in order to be a covered item and paid for by insurance - you can pay out of pocket anything else after that fact - if you want to upgrade anything thats not covered

for the most part a group 3 chair here - for example a 636 not made any more - is enough for anyone - insurance covers it - it may not cover a fancy JS large color screen - those are items that dont make the chair run any better - so its not covered - if you like to get it - you can - or order it with everything you want - even if its not covered - get denied mostly - appeal and fair hearing and 99 percent you get it covered after that

but if you want to avoid all the extra effort - take the standard group 3 chair - should work fine for just about everyone - the problem if they are not making a RWD Chair at all - we screwed - its not being offered so cant order one - no matter what group class it may be in -

the new 500H - is a group 3 chair - but as you order one - you have upgrades if you want - Rnet 120 is not standard - fast motors are not standard - large color JS is not standard - Tilt and recline you can get - but seat lift they will fight you on it - insurance -


bottom line if sunrise dosnt make a RWD chair for the US - groups dont matter - i bet they wont bring RWD chair here and stay with that 500H only -

[fishinjunky]

yes the insurance has a guide line to meet those specs in order to be a covered item and paid for by insurance - you can pay out of pocket anything else after that fact - if you want to upgrade anything thats not covered

for the most part a group 3 chair here - for example a 636 not made any more - is enough for anyone - insurance covers it - it may not cover a fancy JS large color screen - those are items that dont make the chair run any better - so its not covered - if you like to get it - you can - or order it with everything you want - even if its not covered - get denied mostly - appeal and fair hearing and 99 percent you get it covered after that

but if you want to avoid all the extra effort - take the standard group 3 chair - should work fine for just about everyone - the problem if they are not making a RWD Chair at all - we screwed - its not being offered so cant order one - no matter what group class it may be in -

the new 500H - is a group 3 chair - but as you order one - you have upgrades if you want - Rnet 120 is not standard - fast motors are not standard - large color JS is not standard - Tilt and recline you can get - but seat lift they will fight you on it - insurance -


bottom line if sunrise dosnt make a RWD chair for the US - groups dont matter - i bet they wont bring RWD chair here and stay with that 500H only -

Now you got me pumped up for a group 4 fight when the time comes for a new chair lol yea If sunrise doesn't have a rwd in the U.S in the next 5 years when I can get a new chair I'm not sure what I'll get. Another bounder maybe a v4 or v6

[expresso]

what you can normally do - is they dont really want to do a group 4 chair outright - so in my case - i do a group 3 chair - and add the items i want - which in turn makes it a group 4 -

but i had to fight for them - seat lift - larger color display - which may not be that great - holding it etc, - seems its giving me a harder time than the smaller permoble model

motors etc,

BUT if sunrise dosnt get any real RWD chairs here - if its just the 500H - we screwed - go to the V4 RWD - only problem there is the speed - at least for me - they have no option at all for faster motors - even 8 is fine - but they dont have them.

sunrise still offers an 8 - thats an upgrade - and you cant get it if you get a seat lift - you would have to get them yourself either way

on the 500H - not much to fight about - you would fight for the seat lift - and if you want to upgrade to Rnet 120 - color JS etc,

Sunrise did not want to do Rnet 120 unless i got the 8.5 mph motors - so if the 500H will be built with a seat lift - you wont get the motors and wont get the Rnet 120 either

in the end - no worries - you be fine with 90A also - and if you wanted - ebay 120 PM and JS if you want to spend money -

i would just get it best way you can - with out paying nothing - use it - you be happy with it - if not - then you do it yourself

if you went with the 500H - if they dont get any others - forget Pride - leaves V4 RWD - and if invacare brings a new RWD here -

i dont like there electronics and swing aways are crap - sunrise new swing away isnt great - flimsy to me

[Burgerman]

but i had to fight for them - seat lift - larger color display - which may not be that great - holding it etc, - seems its giving me a harder time than the smaller permoble model

You do realise that the only difference is two buttons (where you dont hold) it and a smaller screen (where you dont or shouldnt hold it) right? The bit that matters as far as using it is concerned is basically same size, shape, etc. How can it possibly feel different?

It can only be configured so its in a different place, or the arm top is in a different place. You do have some very odd ideas.
The joystick and base is the same width, same eight, same depth, with the same joystick in it. Only the screen / buttons missing is different. So what you say cannot make any sense. The part that matters is almost identical. The only real difference is the rubber gaitor.

Your own picture of the proper R-Net controller with its bigger brighter screen, and the cheap nasty permobil only one - anything to save them $$$. They use worse parts and charge double.

[expresso]

you can see it in the picture


its different where the JS knob is - that little difference which seems like nothing is something

i hold it different - i am 100% when i go to my old chair - it feels better

i really dont mind it being a smaller screen actually - bigger better - isnt always better

i have to keep adjusting it - position and length - i seem to hold the smaller one better - nothing i can do about it now -

i didnt sit in both chairs to take measurements of my arm length - etc, i will - to see if there is a difference between the seating on both

i know there is a small difference - not sure if thats one reason -

[Burgerman]

The difference you see is because the rubber gaiter is thinner on the R-Net one. Otherwise its almost identical. Those are available on eBay. It cannot be that minute difference that makes it better or worse to use. Its more likely to be the height, length away and the gap between arm top and joystick and how inboard it is. I make mine all feel the same. So every chair feels almost the same even if a different make/whatever.

[expresso]

its a bit wider at the base where the JS knob is - - but yes i dont think its that alone thats causing my issues -

its a mix of things - just feels better to ride my old chair - the way i handle it etc, - i will try a few things - but if i knew before - i would not have went for this JS -

its how i am sitting on my old chair compared to the new one - its a bit different - - i will measure arm length when i am sitting in the next time - the old chair -

when the tech comes back - i will do it - so he can see how i sit in one chair - then the other- he may be able to see it -

i may have to move it up more - making it longer and longer - pretty soon they will pass my foot plates

[Burgerman]

Heres what I do.
I take a chair that I spent a month fine tuning and getting every little thing perfect for my seating position.

Then I make a list of measurements. With a sheet of paper, and a pen, and a tape measure.
Included in those mass of measurements are very important ones. All are important but these are the most important to begin with.

1. SEAT ANGLE. Dump. I like my chairs at around 6 degrees. It often needs a drill...
2. SEAT DEPTH. My cushions are all 20" deep. So I adjust the space between the seat back where my bum leans on, and the front edge of the seat plate to exactly match. Chairs are adjustable! Allen keys only.

3. I adjust the seat pan/plate to the same width as my cushions, and backside. 18 inches.
4. I then adjust the arm width GAP so that they match the seat cushion. So the arm tops have the same 20 inches space.

5. Seat height. Theres not a huge amount you can do on some chairs. Most are similar here anyway. But measured from the floor I make sure that my chairs are all the same. It often needs a drill... Why is it important? It determines the C of G height. Get it wrong and the chair feels wildly different. Esp if its say an inch higher. That makes an awful tip over backwards chair on a slope. And causes leaning where the road is at an angle and so caster shake problems. And it just feels bad.

6. Then measure the distance from the rear wheel centre to the point where your bum hits the backrest. To gice a good starting point for how har to move the seat back. I inch too far and its too unstable, 1 inch too forwards and it drives like an oil tanker. This is fine tuned when testing later.

7. Centre footrest HEIGHT.
8. Centre footplate FOOT ANGLE. Both should match the measurements of my other chairs exactly.
9. Centre footplate distance/angle from the seat pan front edge. This is where you must test and move it back so the casters dont QUITE touch it when its in the most rearward position with no tilt. Small caster tyres, like the Q700, or a saw taken to the footplate (salsa) may be needed.

10. Controller / joystick position. Needs to be the correct height above the arm top, must have correct gap to the arm top, and be the correct inboard position exactly the same as all my other chairs. Use the measurements. Hacksaw, imagination, rejiging arm tops, and modifying mountings will be required. Arm top positions. So that the front of them ends leaving a gap before the controller. Fix the wobbly swing aways...

11. Arm HEIGHT above seat pan. Whatever it takes so all are the same to a 1/4 of an inch.

And every other thing that may be fractionally different in seating position and that you lean on, touch etc like the headrest position. All exactly matched. Then clone the programming. Then go test CG etc. Once all that is done correctly, every chair feels pretty much identical. YOU are not supposed to adapt to fit it. Or "learn" a new chair. It is supposed to be the opposite way around.

Then every chair no matter what make etc all feel pretty much identical as long as they are all rear or front or mid drive. They all drive so similar that you cannot tell one from another. Othe than harder tyres or suspension. And that too is adjustable.

THIS is what I consider the basic setup of a new chair. That your tech/delivery guy SHOULD do on every chair. And this is never what happens. And most people use a badly configured chair till it gets replaced, thinking its a "bad" chair. The reality is theres no bad chairs. Really. Just badly set up for you.

Untill the above is sorted, with bolts, spacers, adjustments, saws and drills I dont even sit in them. Whats the point I already know it will feel crap.

[fishinjunky]

THIS is what I consider the basic setup of a new chair. That your tech/delivery guy SHOULD do on every chair. And this is never what happens. And most people use a badly configured chair till it gets replaced, thinking its a "bad" chair. The reality is theres no bad chairs. Really. Just badly set up for you.

true this is what i went through with my very first chair until i rebuilt it and did the seating correctly then it was like a completely new chair and i was able to drive it without being in awkward positions

[expresso]

the strange thing is - out of all the chairs - the bounder was the only chair and still is - that needed nothing changed or adjusted

the only thing i had them do was change the swing aways - the first set was too large - i had them send another set - more of a 80 degree one that was much better -

other than that - nothing was needed - i had the seat moved back from bounder when they built it - offset -

everyone is so scared of this bounder - when it turns out - its one of my best chair - with some Cons of course - but seating wise - i felt and feel fine right out of the box -

moving to my other chairs - all need something done to them - and the reason i feel is - the seating is done by another company - on a base that it was not really built for seat lift -

its a Pro and a Con - dosnt matter now - my quickie chairs are no longer being made - the bounder is my best chair for fun - speed - etc,

but not as an Only chair in the house - in the end - who knows if nothing good is around when i am ready for another chair - maybe i get another bounder - with Rnet - i have alot of time before then

[fishinjunky]

the strange thing is - out of all the chairs - the bounder was the only chair and still is - that needed nothing changed or adjusted

the only thing i had them do was change the swing aways - the first set was too large - i had them send another set - more of a 80 degree one that was much better -

other than that - nothing was needed - i had the seat moved back from bounder when they built it - offset -

everyone is so scared of this bounder - when it turns out - its one of my best chair - with some Cons of course - but seating wise - i felt and feel fine right out of the box -

moving to my other chairs - all need something done to them - and the reason i feel is - the seating is done by another company - on a base that it was not really built for seat lift -

its a Pro and a Con - dosnt matter now - my quickie chairs are no longer being made - the bounder is my best chair for fun - speed - etc,

but not as an Only chair in the house - in the end - who knows if nothing good is around when i am ready for another chair - maybe i get another bounder - with Rnet - i have alot of time before then

Yea I really like my bounder alot. I got awhile to 5 years. If quickie doesn't offer the q500r or q700r in the U.S in the next 5 years. I'm going to get another bounder and just rebuild my tdx sp again for indoors

[Jay_x]

My search for a new chair is getting more and more frustrating.

My VA rep says she has had so many issues and problem with Invacare chairs that she won't even deal with them anymore. This is news to me. But then again I haven't paid much attention to Invacare before, so I don't know.

Looking at the Quickie q500H which is the closes thing they now have to a RWD chair - what the hell are those tiny wheels in the back doing anyway? Why are they there? Why not just lift them off the ground and turn them into basic anti tipping wheels? How is this "hybrid" nonsense benefitting me somehow?

Ugh. I don't know what the fuck I am going to do now.

[Jay_x]

If it were me and I was getting a new chair right now in the U.S it would come down to three choices

Quickie hybrid q500h (not rear wheel drive) (r-net)
https://www.sunrisemedical.com/power-wh ... ive/q500-h

Amy Systems hybrid Alltrack r3 hybrid (not rear wheel drive) (r-net)
https://amylior.com/amysystems-alltrack-r-series/

Invacare Aviva Storm RX rear wheel drive (linx)
http://www.invacare.com/cgi-bin/imhqprd ... -536892393

Looking at that Alltrack, its the same thing as the Quickie Q500 - a hybrid between RWD and MWD.

[Burgerman]

You need to ignore the bullshit and take a look at the invacare one for a start. All chairs are pretty much equally reliable/unreliable and use the same basic technology, same industry supplyers, and are all pretty simple things in so far as the basic battery/controller/motor setup. I see no reason that invacare should be any less or more reliable than any other.

The one exception seems to be permobil as they dont use industry standard control system as they are produced like the two main ones Dynamic, and PGs R-net. And seem to want to make their own seating, and gyro modules, some joysticks etc. And these can be problematic if you look at all the issues on here. And it seems they cant even diagnose or fix their own systems. And you have no choice but to rely on them...

Whats wrong with the rear drive V6 (the V4 everywhere else) by magic mobility? Size? Ye its a tank of a thing. Depends on where you live and go.

The q500H is really a mid drive layout with limited suspension. Its drive wheel is a little too far forwards for a pure rear drive so needs those wheels on the deck behind you for stability.

You may also want to ask Sunrise if they plan on bringing the Q500R or Q700R to the US/Canada anytime soon. You might be surprised. And I dont mean a rep or some phone call receptionist or something! Because its an obvious hole on the market that their competitors just filled with the Avira rear drive. That too has been available in the rest of the world for a long while.

[expresso]

those little wheels that stay on the ground - in there eyes are for your saftely - chair wont tip back at all - going up hills etc, - alot of people dont like the tipping back feeling - i dont like them on the ground - maybe when i am Older - i may not care

the other chair is the V4 RWD


if you did the 500H - you can try to do something with those little wheels in the rear - or if you just add larger tires 350-8 - that would raise them up automatically - in that case - have no idea how that would affect the chair - ride

at least on the 636 chairs - they are off the ground on mines and have tension on them when tipping back etc,

i dont know if the 500H has the same tension - if they give a bit or are just solid on the ground

[Burgerman]

The 500H has to have the small wheels permanantly pressed onto the deck. Its suspension system and design is a mid wheel drIve setup. Its not a rear drive with rear casters. It has limited drive wheel suspension and its drive wheel is too far forwards to be used as a rear drive directly. You would need to make a few changes, and probably move the seat forwards some as well as fit anti tips. But its wheelbase would still be a bit short. And so not very pitch stable.

I might do it, and would likelt need to take a saw to it or move the rear wheels/motors rearwards 1 to 2 inches. Maybe change the way the suspension works. But its not as simple as it looks.

[Jay_x]

I gues this is what my VA rep is talking about

[img]

FDA identifies more problems at Invacare Corp.

https://www.modernhealthcare.com/articl ... acare-corp


[/img]

[Burgerman]

Thats not reliability. Its quality control. And somehow related to the FDA. That only applied in the US. They have continued selling and designing more modern chairs in the rest of the world and ignoring the US market regardless. Again I dont see how that relates to end user reliability. It seems to refer to a fire issue that affected some US chairs many yers ago and 2 automatic welding machines causeing some warranty parts failure on some chair parts and some bed frames.

Those sort of problems can happen to any production facility. Its not going to cause you to break down or stop in the street.

Ignore the stories and look at the build quality and design yourself! Remember that they dont make the wheels, tyres, bearings, motors, control systems, actuators, etc. They only buy all those industry standard parts parts in from a common group if industry suppliers. Thats why you find for e.g Linix or AMT and 3 or 4 other motors and Dynamic, or Curtis, or PGs R-Net controls on many differnt manufacturers chairs. Although invacare own dynamic now as a seperate company. But again they sell across the industry. What does a powerchair manufacturer actually make? Ignoring permobil who make terrible verions of their own stuff, they basically make the frames and some of the seating system metalwork but not all of them. And some covers and plastic parts. But even many of those are bought in too. So they are basically an assembly of the same parts... In different combinations marketed as something new/better/different.

[Jay_x]

You need to ignore the bullshit and take a look at the invacare one for a start. All chairs are pretty much equally reliable/unreliable and use the same basic technology, same industry supplyers, and are all pretty simple things in so far as the basic battery/controller/motor setup. I see no reason that invacare should be any less or more reliable than any other.
.

If thats the case then why not get the Quantum that my rep is trying so hard to push?

[Burgerman]

Because theres no way to program that. Its totally locked down, dealer mode only. And it depends which one. The early ones had no suspension. The rival does. But again it has that huge programming thing against it.

Ask him if you can get an OEM programmer with that!

Again if you dont care, try it. Or at least take a look. You dont have a lot of choice.

[Fusiongoat]

I gues this is what my VA rep is talking about

[img]

FDA identifies more problems at Invacare Corp.

https://www.modernhealthcare.com/articl ... acare-corp


[/img]

These issues have been resolved https://www.hmenews.com/article/fda-lif ... ent-decree
Who cares what your VA rep thinks? They can't just force you to get a particular chair unless you let them. Just say something like "I wouldn't feel safe driving a Quantum because I don't like how it feels." Don't give an objective reason because they can disagree with that. I like the Amy R3 because it looks like you can get 6.5 mph 4 pole motors and 120A R-net on it and no other manufacture offers that speed of 4 pole motors with 120A R-net in the US. Soon the Magic 360 will be available with that combo, but it's MWD. The Rival uses 90A Q-Logic 2, I think. Quantums are junk and that's just a fact. My order for the V6 MWD was finally submitted to insurance, but Amysystems' chairs have nice options,

[Burgerman]

What specifically fails on a quantum chair? The only thing I see wrong is that I cant program it properly and so was never interested. They use all the same parts as all the other manufacturers. Motors for example like electrocraft. As long as you order the right spec such as 4 pole motors, etc they should have exactly the same reliability.

[expresso]

they look ugly and feel too bulky - a long time ago - i had a demo of the R4000 older version - didnt like it at all once i started to use it - glad i did - at that time - i was almost interested in it

[Burgerman]

4000 has solid tyres, and no suspension, and is very nose heavy with a huge ass and cant be programmed. Run away.

The rival is also nose heavy (extremely - it sits you on the front casters!) but a much better bet once sorted. Which should be relatively easy. But the fact that theres no way to properly program it, totally rules it out for me. It wouldnt get any consideration at all. Proper programming access is Priority no. 1. Its about time manufacturers realised this.

If I lived in the US and had little choice, then I might move the seat back a LOT, fit narrow heel centre plate to allow that properly (not the godawful pride 3 foot long plank ones) and just convert it over to R-Net. Then it should be as good as any other rear drive. But it certainly needs some work to make it a usable chair. Stock ones are so nose heavy as to be terrible in use. Any picture shows that very clearly. https://www.quantumrehab.com/pdf/brochu ... _rival.pdf

But not many people have the confidence or ability to do that. And are relying on the "system" and so you get what you are given and put up with it.

[Jay_x]

VA rep is sending a quantum here for me to try out for a couple days. They ordered one for someone and that person died so I get to try out their chair.

we will see how it goes

[Burgerman]

Testing chairs that are not fully sorted for you, and in the case of that chair by moving the seat back too, will not really help much if at all. One small thing wrong can make a good chair feel or behave terrible. So keep an open mind and look carefully to see what can be done and analise whats wrong. But programming wise you are pretty much screwed.

Its going to feel around 2 feet too long as it comes and you are sat around 4 inches too far forwards over the front of the chair. So it will feel like an oil tanker indoors as it wont turn properly either. So theres that! So it wont turn on place well. And the delayed action programming will disguise this so you think its a programming issue. But report back with findings!